[thirdparty/openssl.git] / ssl / statem / extensions_cust.c

/*
 * Copyright 2014-2023 The OpenSSL Project Authors. All Rights Reserved.
 *
 * Licensed under the Apache License 2.0 (the "License").  You may not use
 * this file except in compliance with the License.  You can obtain a copy
 * in the file LICENSE in the source distribution or at
 * https://www.openssl.org/source/license.html
 */

/* Custom extension utility functions */

#include <openssl/ct.h>
#include "../ssl_local.h"
#include "internal/cryptlib.h"
#include "statem_local.h"

typedef struct {
    void *add_arg;
    custom_ext_add_cb add_cb;
    custom_ext_free_cb free_cb;
} custom_ext_add_cb_wrap;

typedef struct {
    void *parse_arg;
    custom_ext_parse_cb parse_cb;
} custom_ext_parse_cb_wrap;

/*
 * Provide thin wrapper callbacks which convert new style arguments to old style
 */
static int custom_ext_add_old_cb_wrap(SSL *s, unsigned int ext_type,
                                      unsigned int context,
                                      const unsigned char **out,
                                      size_t *outlen, X509 *x, size_t chainidx,
                                      int *al, void *add_arg)
{
    custom_ext_add_cb_wrap *add_cb_wrap = (custom_ext_add_cb_wrap *)add_arg;

    if (add_cb_wrap->add_cb == NULL)
        return 1;

    return add_cb_wrap->add_cb(s, ext_type, out, outlen, al,
                               add_cb_wrap->add_arg);
}

static void custom_ext_free_old_cb_wrap(SSL *s, unsigned int ext_type,
                                        unsigned int context,
                                        const unsigned char *out, void *add_arg)
{
    custom_ext_add_cb_wrap *add_cb_wrap = (custom_ext_add_cb_wrap *)add_arg;

    if (add_cb_wrap->free_cb == NULL)
        return;

    add_cb_wrap->free_cb(s, ext_type, out, add_cb_wrap->add_arg);
}

static int custom_ext_parse_old_cb_wrap(SSL *s, unsigned int ext_type,
                                        unsigned int context,
                                        const unsigned char *in,
                                        size_t inlen, X509 *x, size_t chainidx,
                                        int *al, void *parse_arg)
{
    custom_ext_parse_cb_wrap *parse_cb_wrap =
        (custom_ext_parse_cb_wrap *)parse_arg;

    if (parse_cb_wrap->parse_cb == NULL)
        return 1;

    return parse_cb_wrap->parse_cb(s, ext_type, in, inlen, al,
                                   parse_cb_wrap->parse_arg);
}

/*
 * Find a custom extension from the list. The |role| param is there to
 * support the legacy API where custom extensions for client and server could
 * be set independently on the same SSL_CTX. It is set to ENDPOINT_SERVER if we
 * are trying to find a method relevant to the server, ENDPOINT_CLIENT for the
 * client, or ENDPOINT_BOTH for either
 */
custom_ext_method *custom_ext_find(const custom_ext_methods *exts,
                                   ENDPOINT role, unsigned int ext_type,
                                   size_t *idx)
{
    size_t i;
    custom_ext_method *meth = exts->meths;

    for (i = 0; i < exts->meths_count; i++, meth++) {
        if (ext_type == meth->ext_type
                && (role == ENDPOINT_BOTH || role == meth->role
                    || meth->role == ENDPOINT_BOTH)) {
            if (idx != NULL)
                *idx = i;
            return meth;
        }
    }
    return NULL;
}

/*
 * Initialise custom extensions flags to indicate neither sent nor received.
 */
void custom_ext_init(custom_ext_methods *exts)
{
    size_t i;
    custom_ext_method *meth = exts->meths;

    for (i = 0; i < exts->meths_count; i++, meth++)
        meth->ext_flags = 0;
}

/* Pass received custom extension data to the application for parsing. */
int custom_ext_parse(SSL_CONNECTION *s, unsigned int context,
                     unsigned int ext_type,
                     const unsigned char *ext_data, size_t ext_size, X509 *x,
                     size_t chainidx)
{
    int al;
    custom_ext_methods *exts = &s->cert->custext;
    custom_ext_method *meth;
    ENDPOINT role = ENDPOINT_BOTH;

    if ((context & (SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_2_SERVER_HELLO)) != 0)
        role = s->server ? ENDPOINT_SERVER : ENDPOINT_CLIENT;

    meth = custom_ext_find(exts, role, ext_type, NULL);
    /* If not found return success */
    if (!meth)
        return 1;

    /* Check if extension is defined for our protocol. If not, skip */
    if (!extension_is_relevant(s, meth->context, context))
        return 1;

    if ((context & (SSL_EXT_TLS1_2_SERVER_HELLO
                    | SSL_EXT_TLS1_3_SERVER_HELLO
                    | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS)) != 0) {
        /*
         * If it's ServerHello or EncryptedExtensions we can't have any
         * extensions not sent in ClientHello.
         */
        if ((meth->ext_flags & SSL_EXT_FLAG_SENT) == 0) {
            SSLfatal(s, TLS1_AD_UNSUPPORTED_EXTENSION, SSL_R_BAD_EXTENSION);
            return 0;
        }
    }

    /*
     * Extensions received in the ClientHello or CertificateRequest are marked
     * with the SSL_EXT_FLAG_RECEIVED. This is so we know to add the equivalent
     * extensions in the response messages
     */
    if ((context & (SSL_EXT_CLIENT_HELLO | SSL_EXT_TLS1_3_CERTIFICATE_REQUEST))
            != 0)
        meth->ext_flags |= SSL_EXT_FLAG_RECEIVED;

    /* If no parse function set return success */
    if (meth->parse_cb == NULL)
        return 1;

    if (meth->parse_cb(SSL_CONNECTION_GET_SSL(s), ext_type, context, ext_data,
                       ext_size, x, chainidx, &al, meth->parse_arg) <= 0) {
        SSLfatal(s, al, SSL_R_BAD_EXTENSION);
        return 0;
    }

    return 1;
}

/*
 * Request custom extension data from the application and add to the return
 * buffer.
 */
int custom_ext_add(SSL_CONNECTION *s, int context, WPACKET *pkt, X509 *x,
                   size_t chainidx, int maxversion)
{
    custom_ext_methods *exts = &s->cert->custext;
    custom_ext_method *meth;
    size_t i;
    int al;
    int for_comp = (context & SSL_EXT_TLS1_3_CERTIFICATE_COMPRESSION) != 0;

    for (i = 0; i < exts->meths_count; i++) {
        const unsigned char *out = NULL;
        size_t outlen = 0;

        meth = exts->meths + i;

        if (!should_add_extension(s, meth->context, context, maxversion))
            continue;

        if ((context & (SSL_EXT_TLS1_2_SERVER_HELLO
                        | SSL_EXT_TLS1_3_SERVER_HELLO
                        | SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS
                        | SSL_EXT_TLS1_3_CERTIFICATE
                        | SSL_EXT_TLS1_3_RAW_PUBLIC_KEY
                        | SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST)) != 0) {
            /* Only send extensions present in ClientHello/CertificateRequest */
            if (!(meth->ext_flags & SSL_EXT_FLAG_RECEIVED))
                continue;
        }
        /*
         * We skip it if the callback is absent - except for a ClientHello where
         * we add an empty extension.
         */
        if ((context & SSL_EXT_CLIENT_HELLO) == 0 && meth->add_cb == NULL)
            continue;

        if (meth->add_cb != NULL) {
            int cb_retval = meth->add_cb(SSL_CONNECTION_GET_SSL(s),
                                         meth->ext_type, context, &out,
                                         &outlen, x, chainidx, &al,
                                         meth->add_arg);

            if (cb_retval < 0) {
                if (!for_comp)
                    SSLfatal(s, al, SSL_R_CALLBACK_FAILED);
                return 0;       /* error */
            }
            if (cb_retval == 0)
                continue;       /* skip this extension */
        }

        if (!WPACKET_put_bytes_u16(pkt, meth->ext_type)
                || !WPACKET_start_sub_packet_u16(pkt)
                || (outlen > 0 && !WPACKET_memcpy(pkt, out, outlen))
                || !WPACKET_close(pkt)) {
            if (!for_comp)
                SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
            return 0;
        }
        if ((context & SSL_EXT_CLIENT_HELLO) != 0) {
            /*
             * We can't send duplicates: code logic should prevent this.
             */
            if (!ossl_assert((meth->ext_flags & SSL_EXT_FLAG_SENT) == 0)) {
                if (!for_comp)
                    SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
                return 0;
            }
            /*
             * Indicate extension has been sent: this is both a sanity check to
             * ensure we don't send duplicate extensions and indicates that it
             * is not an error if the extension is present in ServerHello.
             */
            meth->ext_flags |= SSL_EXT_FLAG_SENT;
        }
        if (meth->free_cb != NULL)
            meth->free_cb(SSL_CONNECTION_GET_SSL(s), meth->ext_type, context,
                          out, meth->add_arg);
    }
    return 1;
}

/* Copy the flags from src to dst for any extensions that exist in both */
int custom_exts_copy_flags(custom_ext_methods *dst,
                           const custom_ext_methods *src)
{
    size_t i;
    custom_ext_method *methsrc = src->meths;

    for (i = 0; i < src->meths_count; i++, methsrc++) {
        custom_ext_method *methdst = custom_ext_find(dst, methsrc->role,
                                                     methsrc->ext_type, NULL);

        if (methdst == NULL)
            continue;

        methdst->ext_flags = methsrc->ext_flags;
    }

    return 1;
}

/* Copy table of custom extensions */
int custom_exts_copy(custom_ext_methods *dst, const custom_ext_methods *src)
{
    size_t i;
    int err = 0;

    if (src->meths_count > 0) {
        dst->meths =
            OPENSSL_memdup(src->meths,
                           sizeof(*src->meths) * src->meths_count);
        if (dst->meths == NULL)
            return 0;
        dst->meths_count = src->meths_count;

        for (i = 0; i < src->meths_count; i++) {
            custom_ext_method *methsrc = src->meths + i;
            custom_ext_method *methdst = dst->meths + i;

            if (methsrc->add_cb != custom_ext_add_old_cb_wrap)
                continue;

            /*
             * We have found an old style API wrapper. We need to copy the
             * arguments too.
             */

            if (err) {
                methdst->add_arg = NULL;
                methdst->parse_arg = NULL;
                continue;
            }

            methdst->add_arg = OPENSSL_memdup(methsrc->add_arg,
                                              sizeof(custom_ext_add_cb_wrap));
            methdst->parse_arg = OPENSSL_memdup(methsrc->parse_arg,
                                            sizeof(custom_ext_parse_cb_wrap));

            if (methdst->add_arg == NULL || methdst->parse_arg == NULL)
                err = 1;
        }
    }

    if (err) {
        custom_exts_free(dst);
        return 0;
    }

    return 1;
}

void custom_exts_free(custom_ext_methods *exts)
{
    size_t i;
    custom_ext_method *meth;

    for (i = 0, meth = exts->meths; i < exts->meths_count; i++, meth++) {
        if (meth->add_cb != custom_ext_add_old_cb_wrap)
            continue;

        /* Old style API wrapper. Need to free the arguments too */
        OPENSSL_free(meth->add_arg);
        OPENSSL_free(meth->parse_arg);
    }
    OPENSSL_free(exts->meths);
}

/* Return true if a client custom extension exists, false otherwise */
int SSL_CTX_has_client_custom_ext(const SSL_CTX *ctx, unsigned int ext_type)
{
    return custom_ext_find(&ctx->cert->custext, ENDPOINT_CLIENT, ext_type,
                           NULL) != NULL;
}

int ossl_tls_add_custom_ext_intern(SSL_CTX *ctx, custom_ext_methods *exts,
                                   ENDPOINT role, unsigned int ext_type,
                                   unsigned int context,
                                   SSL_custom_ext_add_cb_ex add_cb,
                                   SSL_custom_ext_free_cb_ex free_cb,
                                   void *add_arg,
                                   SSL_custom_ext_parse_cb_ex parse_cb,
                                   void *parse_arg)
{
    custom_ext_method *meth, *tmp;

    /*
     * Check application error: if add_cb is not set free_cb will never be
     * called.
     */
    if (add_cb == NULL && free_cb != NULL)
        return 0;

    if (exts == NULL)
        exts = &ctx->cert->custext;

#ifndef OPENSSL_NO_CT
    /*
     * We don't want applications registering callbacks for SCT extensions
     * whilst simultaneously using the built-in SCT validation features, as
     * these two things may not play well together.
     */
    if (ext_type == TLSEXT_TYPE_signed_certificate_timestamp
            && (context & SSL_EXT_CLIENT_HELLO) != 0
            && ctx != NULL
            && SSL_CTX_ct_is_enabled(ctx))
        return 0;
#endif

    /*
     * Don't add if extension supported internally, but make exception
     * for extension types that previously were not supported, but now are.
     */
    if (SSL_extension_supported(ext_type)
            && ext_type != TLSEXT_TYPE_signed_certificate_timestamp)
        return 0;

    /* Extension type must fit in 16 bits */
    if (ext_type > 0xffff)
        return 0;
    /* Search for duplicate */
    if (custom_ext_find(exts, role, ext_type, NULL))
        return 0;
    tmp = OPENSSL_realloc(exts->meths,
                          (exts->meths_count + 1) * sizeof(custom_ext_method));
    if (tmp == NULL)
        return 0;

    exts->meths = tmp;
    meth = exts->meths + exts->meths_count;
    memset(meth, 0, sizeof(*meth));
    meth->role = role;
    meth->context = context;
    meth->parse_cb = parse_cb;
    meth->add_cb = add_cb;
    meth->free_cb = free_cb;
    meth->ext_type = ext_type;
    meth->add_arg = add_arg;
    meth->parse_arg = parse_arg;
    exts->meths_count++;
    return 1;
}

static int add_old_custom_ext(SSL_CTX *ctx, ENDPOINT role,
                              unsigned int ext_type,
                              unsigned int context,
                              custom_ext_add_cb add_cb,
                              custom_ext_free_cb free_cb,
                              void *add_arg,
                              custom_ext_parse_cb parse_cb, void *parse_arg)
{
    custom_ext_add_cb_wrap *add_cb_wrap
        = OPENSSL_malloc(sizeof(*add_cb_wrap));
    custom_ext_parse_cb_wrap *parse_cb_wrap
        = OPENSSL_malloc(sizeof(*parse_cb_wrap));
    int ret;

    if (add_cb_wrap == NULL || parse_cb_wrap == NULL) {
        OPENSSL_free(add_cb_wrap);
        OPENSSL_free(parse_cb_wrap);
        return 0;
    }

    add_cb_wrap->add_arg = add_arg;
    add_cb_wrap->add_cb = add_cb;
    add_cb_wrap->free_cb = free_cb;
    parse_cb_wrap->parse_arg = parse_arg;
    parse_cb_wrap->parse_cb = parse_cb;

    ret = ossl_tls_add_custom_ext_intern(ctx, NULL, role, ext_type,
                                         context,
                                         custom_ext_add_old_cb_wrap,
                                         custom_ext_free_old_cb_wrap,
                                         add_cb_wrap,
                                         custom_ext_parse_old_cb_wrap,
                                         parse_cb_wrap);

    if (!ret) {
        OPENSSL_free(add_cb_wrap);
        OPENSSL_free(parse_cb_wrap);
    }

    return ret;
}

/* Application level functions to add the old custom extension callbacks */
int SSL_CTX_add_client_custom_ext(SSL_CTX *ctx, unsigned int ext_type,
                                  custom_ext_add_cb add_cb,
                                  custom_ext_free_cb free_cb,
                                  void *add_arg,
                                  custom_ext_parse_cb parse_cb, void *parse_arg)
{
    return add_old_custom_ext(ctx, ENDPOINT_CLIENT, ext_type,
                              SSL_EXT_TLS1_2_AND_BELOW_ONLY
                              | SSL_EXT_CLIENT_HELLO
                              | SSL_EXT_TLS1_2_SERVER_HELLO
                              | SSL_EXT_IGNORE_ON_RESUMPTION,
                              add_cb, free_cb, add_arg, parse_cb, parse_arg);
}

int SSL_CTX_add_server_custom_ext(SSL_CTX *ctx, unsigned int ext_type,
                                  custom_ext_add_cb add_cb,
                                  custom_ext_free_cb free_cb,
                                  void *add_arg,
                                  custom_ext_parse_cb parse_cb, void *parse_arg)
{
    return add_old_custom_ext(ctx, ENDPOINT_SERVER, ext_type,
                              SSL_EXT_TLS1_2_AND_BELOW_ONLY
                              | SSL_EXT_CLIENT_HELLO
                              | SSL_EXT_TLS1_2_SERVER_HELLO
                              | SSL_EXT_IGNORE_ON_RESUMPTION,
                              add_cb, free_cb, add_arg, parse_cb, parse_arg);
}

int SSL_CTX_add_custom_ext(SSL_CTX *ctx, unsigned int ext_type,
                           unsigned int context,
                           SSL_custom_ext_add_cb_ex add_cb,
                           SSL_custom_ext_free_cb_ex free_cb,
                           void *add_arg,
                           SSL_custom_ext_parse_cb_ex parse_cb, void *parse_arg)
{
    return ossl_tls_add_custom_ext_intern(ctx, NULL, ENDPOINT_BOTH, ext_type,
                                          context, add_cb, free_cb, add_arg,
                                          parse_cb, parse_arg);
}

int SSL_extension_supported(unsigned int ext_type)
{
    switch (ext_type) {
        /* Internally supported extensions. */
    case TLSEXT_TYPE_application_layer_protocol_negotiation:
    case TLSEXT_TYPE_ec_point_formats:
    case TLSEXT_TYPE_supported_groups:
    case TLSEXT_TYPE_key_share:
#ifndef OPENSSL_NO_NEXTPROTONEG
    case TLSEXT_TYPE_next_proto_neg:
#endif
    case TLSEXT_TYPE_padding:
    case TLSEXT_TYPE_renegotiate:
    case TLSEXT_TYPE_max_fragment_length:
    case TLSEXT_TYPE_server_name:
    case TLSEXT_TYPE_session_ticket:
    case TLSEXT_TYPE_signature_algorithms:
#ifndef OPENSSL_NO_SRP
    case TLSEXT_TYPE_srp:
#endif
#ifndef OPENSSL_NO_OCSP
    case TLSEXT_TYPE_status_request:
#endif
#ifndef OPENSSL_NO_CT
    case TLSEXT_TYPE_signed_certificate_timestamp:
#endif
#ifndef OPENSSL_NO_SRTP
    case TLSEXT_TYPE_use_srtp:
#endif
    case TLSEXT_TYPE_encrypt_then_mac:
    case TLSEXT_TYPE_supported_versions:
    case TLSEXT_TYPE_extended_master_secret:
    case TLSEXT_TYPE_psk_kex_modes:
    case TLSEXT_TYPE_cookie:
    case TLSEXT_TYPE_early_data:
    case TLSEXT_TYPE_certificate_authorities:
    case TLSEXT_TYPE_psk:
    case TLSEXT_TYPE_post_handshake_auth:
    case TLSEXT_TYPE_compress_certificate:
    case TLSEXT_TYPE_client_cert_type:
    case TLSEXT_TYPE_server_cert_type:
        return 1;
    default:
        return 0;
    }
}
Commit	Line	Data
846e33c7	1	/*
3c95ef22	2	* Copyright 2014-2023 The OpenSSL Project Authors. All Rights Reserved.
ecf4d660	3	*
2c18d164	4	* Licensed under the Apache License 2.0 (the "License"). You may not use
846e33c7 RS	5	* this file except in compliance with the License. You can obtain a copy
	6	* in the file LICENSE in the source distribution or at
	7	* https://www.openssl.org/source/license.html
ecf4d660 DSH	8	*/
	9
	10	/* Custom extension utility functions */
	11
3c27208f	12	#include <openssl/ct.h>
706457b7	13	#include "../ssl_local.h"
67dc995e	14	#include "internal/cryptlib.h"
706457b7	15	#include "statem_local.h"
ecf4d660	16
43ae5eed MC	17	typedef struct {
	18	void *add_arg;
	19	custom_ext_add_cb add_cb;
	20	custom_ext_free_cb free_cb;
	21	} custom_ext_add_cb_wrap;
	22
	23	typedef struct {
	24	void *parse_arg;
	25	custom_ext_parse_cb parse_cb;
	26	} custom_ext_parse_cb_wrap;
	27
	28	/*
	29	* Provide thin wrapper callbacks which convert new style arguments to old style
	30	*/
	31	static int custom_ext_add_old_cb_wrap(SSL *s, unsigned int ext_type,
	32	unsigned int context,
	33	const unsigned char **out,
	34	size_t outlen, X509 x, size_t chainidx,
	35	int al, void add_arg)
	36	{
	37	custom_ext_add_cb_wrap add_cb_wrap = (custom_ext_add_cb_wrap )add_arg;
	38
	39	if (add_cb_wrap->add_cb == NULL)
	40	return 1;
	41
	42	return add_cb_wrap->add_cb(s, ext_type, out, outlen, al,
	43	add_cb_wrap->add_arg);
	44	}
	45
	46	static void custom_ext_free_old_cb_wrap(SSL *s, unsigned int ext_type,
	47	unsigned int context,
	48	const unsigned char out, void add_arg)
	49	{
	50	custom_ext_add_cb_wrap add_cb_wrap = (custom_ext_add_cb_wrap )add_arg;
	51
	52	if (add_cb_wrap->free_cb == NULL)
	53	return;
	54
	55	add_cb_wrap->free_cb(s, ext_type, out, add_cb_wrap->add_arg);
	56	}
	57
	58	static int custom_ext_parse_old_cb_wrap(SSL *s, unsigned int ext_type,
	59	unsigned int context,
	60	const unsigned char *in,
	61	size_t inlen, X509 *x, size_t chainidx,
	62	int al, void parse_arg)
	63	{
	64	custom_ext_parse_cb_wrap *parse_cb_wrap =
	65	(custom_ext_parse_cb_wrap *)parse_arg;
	66
e596c68c GE	67	if (parse_cb_wrap->parse_cb == NULL)
	68	return 1;
	69
43ae5eed MC	70	return parse_cb_wrap->parse_cb(s, ext_type, in, inlen, al,
	71	parse_cb_wrap->parse_arg);
	72	}
	73
	74	/*
787d9ec7	75	* Find a custom extension from the list. The \|role\| param is there to
43ae5eed	76	* support the legacy API where custom extensions for client and server could
787d9ec7 MC	77	* be set independently on the same SSL_CTX. It is set to ENDPOINT_SERVER if we
	78	* are trying to find a method relevant to the server, ENDPOINT_CLIENT for the
	79	* client, or ENDPOINT_BOTH for either
43ae5eed	80	*/
787d9ec7 MC	81	custom_ext_method custom_ext_find(const custom_ext_methods exts,
	82	ENDPOINT role, unsigned int ext_type,
	83	size_t *idx)
0f113f3e MC	84	{
	85	size_t i;
	86	custom_ext_method *meth = exts->meths;
64350ab5	87
0f113f3e	88	for (i = 0; i < exts->meths_count; i++, meth++) {
43ae5eed	89	if (ext_type == meth->ext_type
787d9ec7 MC	90	&& (role == ENDPOINT_BOTH \|\| role == meth->role
787d9ec7 MC	91	\|\| meth->role == ENDPOINT_BOTH)) {
43ae5eed MC	92	if (idx != NULL)
43ae5eed MC	93	*idx = i;
0f113f3e	94	return meth;
43ae5eed	95	}
0f113f3e MC	96	}
	97	return NULL;
	98	}
	99
	100	/*
	101	* Initialise custom extensions flags to indicate neither sent nor received.
28ea0a0c DSH	102	*/
28ea0a0c DSH	103	void custom_ext_init(custom_ext_methods *exts)
0f113f3e MC	104	{
	105	size_t i;
	106	custom_ext_method *meth = exts->meths;
64350ab5	107
0f113f3e MC	108	for (i = 0; i < exts->meths_count; i++, meth++)
	109	meth->ext_flags = 0;
	110	}
ecf4d660	111
0cfefe4b	112	/* Pass received custom extension data to the application for parsing. */
38b051a1 TM	113	int custom_ext_parse(SSL_CONNECTION *s, unsigned int context,
38b051a1 TM	114	unsigned int ext_type,
43ae5eed	115	const unsigned char ext_data, size_t ext_size, X509 x,
f63a17d6	116	size_t chainidx)
0f113f3e	117	{
f63a17d6	118	int al;
43ae5eed	119	custom_ext_methods *exts = &s->cert->custext;
0f113f3e	120	custom_ext_method *meth;
787d9ec7	121	ENDPOINT role = ENDPOINT_BOTH;
43ae5eed MC	122
43ae5eed MC	123	if ((context & (SSL_EXT_CLIENT_HELLO \| SSL_EXT_TLS1_2_SERVER_HELLO)) != 0)
787d9ec7	124	role = s->server ? ENDPOINT_SERVER : ENDPOINT_CLIENT;
43ae5eed	125
787d9ec7	126	meth = custom_ext_find(exts, role, ext_type, NULL);
0f113f3e MC	127	/* If not found return success */
	128	if (!meth)
	129	return 1;
43ae5eed MC	130
	131	/* Check if extension is defined for our protocol. If not, skip */
	132	if (!extension_is_relevant(s, meth->context, context))
	133	return 1;
	134
	135	if ((context & (SSL_EXT_TLS1_2_SERVER_HELLO
	136	\| SSL_EXT_TLS1_3_SERVER_HELLO
	137	\| SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS)) != 0) {
0f113f3e	138	/*
43ae5eed MC	139	* If it's ServerHello or EncryptedExtensions we can't have any
43ae5eed MC	140	* extensions not sent in ClientHello.
0f113f3e	141	*/
43ae5eed	142	if ((meth->ext_flags & SSL_EXT_FLAG_SENT) == 0) {
c48ffbcc	143	SSLfatal(s, TLS1_AD_UNSUPPORTED_EXTENSION, SSL_R_BAD_EXTENSION);
0f113f3e MC	144	return 0;
	145	}
	146	}
43ae5eed MC	147
43ae5eed MC	148	/*
cbb862fb MC	149	* Extensions received in the ClientHello or CertificateRequest are marked
	150	* with the SSL_EXT_FLAG_RECEIVED. This is so we know to add the equivalent
	151	* extensions in the response messages
43ae5eed	152	*/
cbb862fb MC	153	if ((context & (SSL_EXT_CLIENT_HELLO \| SSL_EXT_TLS1_3_CERTIFICATE_REQUEST))
cbb862fb MC	154	!= 0)
43ae5eed MC	155	meth->ext_flags \|= SSL_EXT_FLAG_RECEIVED;
43ae5eed MC	156
0f113f3e	157	/* If no parse function set return success */
38b051a1	158	if (meth->parse_cb == NULL)
0f113f3e	159	return 1;
ecf4d660	160
38b051a1 TM	161	if (meth->parse_cb(SSL_CONNECTION_GET_SSL(s), ext_type, context, ext_data,
38b051a1 TM	162	ext_size, x, chainidx, &al, meth->parse_arg) <= 0) {
c48ffbcc	163	SSLfatal(s, al, SSL_R_BAD_EXTENSION);
f63a17d6 MC	164	return 0;
	165	}
	166
	167	return 1;
0f113f3e	168	}
ecf4d660	169
2c7b4dbc MC	170	/*
	171	* Request custom extension data from the application and add to the return
	172	* buffer.
	173	*/
38b051a1 TM	174	int custom_ext_add(SSL_CONNECTION s, int context, WPACKET pkt, X509 *x,
38b051a1 TM	175	size_t chainidx, int maxversion)
2c7b4dbc	176	{
43ae5eed	177	custom_ext_methods *exts = &s->cert->custext;
2c7b4dbc MC	178	custom_ext_method *meth;
2c7b4dbc MC	179	size_t i;
f63a17d6	180	int al;
72620ac7	181	int for_comp = (context & SSL_EXT_TLS1_3_CERTIFICATE_COMPRESSION) != 0;
2c7b4dbc MC	182
	183	for (i = 0; i < exts->meths_count; i++) {
	184	const unsigned char *out = NULL;
	185	size_t outlen = 0;
2c7b4dbc MC	186
	187	meth = exts->meths + i;
	188
43ae5eed MC	189	if (!should_add_extension(s, meth->context, context, maxversion))
	190	continue;
	191
	192	if ((context & (SSL_EXT_TLS1_2_SERVER_HELLO
	193	\| SSL_EXT_TLS1_3_SERVER_HELLO
7f533d6f MC	194	\| SSL_EXT_TLS1_3_ENCRYPTED_EXTENSIONS
7f533d6f MC	195	\| SSL_EXT_TLS1_3_CERTIFICATE
3c95ef22	196	\| SSL_EXT_TLS1_3_RAW_PUBLIC_KEY
7f533d6f	197	\| SSL_EXT_TLS1_3_HELLO_RETRY_REQUEST)) != 0) {
cbb862fb	198	/* Only send extensions present in ClientHello/CertificateRequest */
2c7b4dbc MC	199	if (!(meth->ext_flags & SSL_EXT_FLAG_RECEIVED))
2c7b4dbc MC	200	continue;
2c7b4dbc	201	}
43ae5eed MC	202	/*
	203	* We skip it if the callback is absent - except for a ClientHello where
	204	* we add an empty extension.
	205	*/
	206	if ((context & SSL_EXT_CLIENT_HELLO) == 0 && meth->add_cb == NULL)
	207	continue;
	208
	209	if (meth->add_cb != NULL) {
38b051a1 TM	210	int cb_retval = meth->add_cb(SSL_CONNECTION_GET_SSL(s),
38b051a1 TM	211	meth->ext_type, context, &out,
f63a17d6	212	&outlen, x, chainidx, &al,
64350ab5 MC	213	meth->add_arg);
64350ab5 MC	214
f63a17d6	215	if (cb_retval < 0) {
72620ac7 TS	216	if (!for_comp)
72620ac7 TS	217	SSLfatal(s, al, SSL_R_CALLBACK_FAILED);
2c7b4dbc	218	return 0; /* error */
f63a17d6	219	}
2c7b4dbc MC	220	if (cb_retval == 0)
	221	continue; /* skip this extension */
	222	}
	223
08029dfa	224	if (!WPACKET_put_bytes_u16(pkt, meth->ext_type)
de451856	225	\|\| !WPACKET_start_sub_packet_u16(pkt)
0217dd19 MC	226	\|\| (outlen > 0 && !WPACKET_memcpy(pkt, out, outlen))
0217dd19 MC	227	\|\| !WPACKET_close(pkt)) {
72620ac7 TS	228	if (!for_comp)
72620ac7 TS	229	SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
2c7b4dbc MC	230	return 0;
2c7b4dbc MC	231	}
43ae5eed MC	232	if ((context & SSL_EXT_CLIENT_HELLO) != 0) {
	233	/*
	234	* We can't send duplicates: code logic should prevent this.
	235	*/
b77f3ed1	236	if (!ossl_assert((meth->ext_flags & SSL_EXT_FLAG_SENT) == 0)) {
72620ac7 TS	237	if (!for_comp)
72620ac7 TS	238	SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
b77f3ed1 MC	239	return 0;
b77f3ed1 MC	240	}
43ae5eed MC	241	/*
	242	* Indicate extension has been sent: this is both a sanity check to
	243	* ensure we don't send duplicate extensions and indicates that it
	244	* is not an error if the extension is present in ServerHello.
	245	*/
	246	meth->ext_flags \|= SSL_EXT_FLAG_SENT;
	247	}
64350ab5	248	if (meth->free_cb != NULL)
38b051a1 TM	249	meth->free_cb(SSL_CONNECTION_GET_SSL(s), meth->ext_type, context,
38b051a1 TM	250	out, meth->add_arg);
2c7b4dbc MC	251	}
	252	return 1;
	253	}
	254
21181889 MC	255	/* Copy the flags from src to dst for any extensions that exist in both */
	256	int custom_exts_copy_flags(custom_ext_methods *dst,
	257	const custom_ext_methods *src)
	258	{
	259	size_t i;
	260	custom_ext_method *methsrc = src->meths;
	261
	262	for (i = 0; i < src->meths_count; i++, methsrc++) {
	263	custom_ext_method *methdst = custom_ext_find(dst, methsrc->role,
	264	methsrc->ext_type, NULL);
	265
	266	if (methdst == NULL)
	267	continue;
	268
	269	methdst->ext_flags = methsrc->ext_flags;
	270	}
	271
	272	return 1;
	273	}
	274
ecf4d660	275	/* Copy table of custom extensions */
ecf4d660	276	int custom_exts_copy(custom_ext_methods dst, const custom_ext_methods src)
0f113f3e	277	{
43ae5eed MC	278	size_t i;
	279	int err = 0;
	280
	281	if (src->meths_count > 0) {
0f113f3e	282	dst->meths =
7644a9ae	283	OPENSSL_memdup(src->meths,
64350ab5	284	sizeof(src->meths) src->meths_count);
0f113f3e MC	285	if (dst->meths == NULL)
	286	return 0;
	287	dst->meths_count = src->meths_count;
43ae5eed MC	288
	289	for (i = 0; i < src->meths_count; i++) {
	290	custom_ext_method *methsrc = src->meths + i;
	291	custom_ext_method *methdst = dst->meths + i;
	292
	293	if (methsrc->add_cb != custom_ext_add_old_cb_wrap)
	294	continue;
	295
	296	/*
	297	* We have found an old style API wrapper. We need to copy the
	298	* arguments too.
	299	*/
	300
	301	if (err) {
	302	methdst->add_arg = NULL;
	303	methdst->parse_arg = NULL;
	304	continue;
	305	}
	306
	307	methdst->add_arg = OPENSSL_memdup(methsrc->add_arg,
	308	sizeof(custom_ext_add_cb_wrap));
	309	methdst->parse_arg = OPENSSL_memdup(methsrc->parse_arg,
	310	sizeof(custom_ext_parse_cb_wrap));
	311
	312	if (methdst->add_arg == NULL \|\| methdst->parse_arg == NULL)
	313	err = 1;
	314	}
	315	}
	316
	317	if (err) {
	318	custom_exts_free(dst);
	319	return 0;
0f113f3e	320	}
43ae5eed	321
0f113f3e MC	322	return 1;
0f113f3e MC	323	}
ecf4d660 DSH	324
ecf4d660 DSH	325	void custom_exts_free(custom_ext_methods *exts)
0f113f3e	326	{
43ae5eed	327	size_t i;
64350ab5	328	custom_ext_method *meth;
43ae5eed	329
64350ab5	330	for (i = 0, meth = exts->meths; i < exts->meths_count; i++, meth++) {
43ae5eed MC	331	if (meth->add_cb != custom_ext_add_old_cb_wrap)
	332	continue;
	333
	334	/* Old style API wrapper. Need to free the arguments too */
	335	OPENSSL_free(meth->add_arg);
	336	OPENSSL_free(meth->parse_arg);
	337	}
b548a1f1	338	OPENSSL_free(exts->meths);
0f113f3e	339	}
ecf4d660	340
43ae5eed MC	341	/* Return true if a client custom extension exists, false otherwise */
43ae5eed MC	342	int SSL_CTX_has_client_custom_ext(const SSL_CTX *ctx, unsigned int ext_type)
0f113f3e	343	{
787d9ec7 MC	344	return custom_ext_find(&ctx->cert->custext, ENDPOINT_CLIENT, ext_type,
787d9ec7 MC	345	NULL) != NULL;
43ae5eed MC	346	}
43ae5eed MC	347
f6da3bbf MC	348	int ossl_tls_add_custom_ext_intern(SSL_CTX ctx, custom_ext_methods exts,
	349	ENDPOINT role, unsigned int ext_type,
	350	unsigned int context,
	351	SSL_custom_ext_add_cb_ex add_cb,
	352	SSL_custom_ext_free_cb_ex free_cb,
	353	void *add_arg,
	354	SSL_custom_ext_parse_cb_ex parse_cb,
	355	void *parse_arg)
43ae5eed	356	{
7c0ef843	357	custom_ext_method meth, tmp;
43ae5eed	358
0f113f3e MC	359	/*
	360	* Check application error: if add_cb is not set free_cb will never be
	361	* called.
	362	*/
64350ab5	363	if (add_cb == NULL && free_cb != NULL)
0f113f3e	364	return 0;
43ae5eed	365
f6da3bbf MC	366	if (exts == NULL)
	367	exts = &ctx->cert->custext;
	368
43ae5eed MC	369	#ifndef OPENSSL_NO_CT
	370	/*
	371	* We don't want applications registering callbacks for SCT extensions
	372	* whilst simultaneously using the built-in SCT validation features, as
	373	* these two things may not play well together.
	374	*/
	375	if (ext_type == TLSEXT_TYPE_signed_certificate_timestamp
	376	&& (context & SSL_EXT_CLIENT_HELLO) != 0
f6da3bbf	377	&& ctx != NULL
43ae5eed MC	378	&& SSL_CTX_ct_is_enabled(ctx))
	379	return 0;
	380	#endif
	381
ed29e82a RP	382	/*
	383	* Don't add if extension supported internally, but make exception
	384	* for extension types that previously were not supported, but now are.
	385	*/
43ae5eed MC	386	if (SSL_extension_supported(ext_type)
43ae5eed MC	387	&& ext_type != TLSEXT_TYPE_signed_certificate_timestamp)
0f113f3e	388	return 0;
43ae5eed	389
0f113f3e MC	390	/* Extension type must fit in 16 bits */
	391	if (ext_type > 0xffff)
	392	return 0;
	393	/* Search for duplicate */
787d9ec7	394	if (custom_ext_find(exts, role, ext_type, NULL))
0f113f3e	395	return 0;
7c0ef843 DSH	396	tmp = OPENSSL_realloc(exts->meths,
7c0ef843 DSH	397	(exts->meths_count + 1) * sizeof(custom_ext_method));
ed874fac	398	if (tmp == NULL)
0f113f3e	399	return 0;
ecf4d660	400
7c0ef843	401	exts->meths = tmp;
0f113f3e	402	meth = exts->meths + exts->meths_count;
16f8d4eb	403	memset(meth, 0, sizeof(*meth));
787d9ec7	404	meth->role = role;
43ae5eed	405	meth->context = context;
0f113f3e MC	406	meth->parse_cb = parse_cb;
	407	meth->add_cb = add_cb;
	408	meth->free_cb = free_cb;
	409	meth->ext_type = ext_type;
	410	meth->add_arg = add_arg;
	411	meth->parse_arg = parse_arg;
	412	exts->meths_count++;
	413	return 1;
	414	}
ecf4d660	415
787d9ec7 MC	416	static int add_old_custom_ext(SSL_CTX *ctx, ENDPOINT role,
787d9ec7 MC	417	unsigned int ext_type,
43ae5eed MC	418	unsigned int context,
	419	custom_ext_add_cb add_cb,
	420	custom_ext_free_cb free_cb,
	421	void *add_arg,
	422	custom_ext_parse_cb parse_cb, void *parse_arg)
ed29e82a	423	{
43ae5eed	424	custom_ext_add_cb_wrap *add_cb_wrap
64350ab5	425	= OPENSSL_malloc(sizeof(*add_cb_wrap));
43ae5eed	426	custom_ext_parse_cb_wrap *parse_cb_wrap
64350ab5	427	= OPENSSL_malloc(sizeof(*parse_cb_wrap));
43ae5eed MC	428	int ret;
	429
	430	if (add_cb_wrap == NULL \|\| parse_cb_wrap == NULL) {
	431	OPENSSL_free(add_cb_wrap);
	432	OPENSSL_free(parse_cb_wrap);
	433	return 0;
	434	}
	435
	436	add_cb_wrap->add_arg = add_arg;
	437	add_cb_wrap->add_cb = add_cb;
	438	add_cb_wrap->free_cb = free_cb;
	439	parse_cb_wrap->parse_arg = parse_arg;
	440	parse_cb_wrap->parse_cb = parse_cb;
	441
f6da3bbf MC	442	ret = ossl_tls_add_custom_ext_intern(ctx, NULL, role, ext_type,
	443	context,
	444	custom_ext_add_old_cb_wrap,
	445	custom_ext_free_old_cb_wrap,
	446	add_cb_wrap,
	447	custom_ext_parse_old_cb_wrap,
	448	parse_cb_wrap);
43ae5eed MC	449
	450	if (!ret) {
	451	OPENSSL_free(add_cb_wrap);
	452	OPENSSL_free(parse_cb_wrap);
	453	}
	454
	455	return ret;
ed29e82a RP	456	}
ed29e82a RP	457
43ae5eed	458	/* Application level functions to add the old custom extension callbacks */
8cafe9e8	459	int SSL_CTX_add_client_custom_ext(SSL_CTX *ctx, unsigned int ext_type,
0f113f3e MC	460	custom_ext_add_cb add_cb,
0f113f3e MC	461	custom_ext_free_cb free_cb,
0cfefe4b	462	void *add_arg,
a230b26e	463	custom_ext_parse_cb parse_cb, void *parse_arg)
0f113f3e	464	{
787d9ec7	465	return add_old_custom_ext(ctx, ENDPOINT_CLIENT, ext_type,
43ae5eed MC	466	SSL_EXT_TLS1_2_AND_BELOW_ONLY
	467	\| SSL_EXT_CLIENT_HELLO
	468	\| SSL_EXT_TLS1_2_SERVER_HELLO
	469	\| SSL_EXT_IGNORE_ON_RESUMPTION,
	470	add_cb, free_cb, add_arg, parse_cb, parse_arg);
0f113f3e	471	}
ecf4d660	472
8cafe9e8	473	int SSL_CTX_add_server_custom_ext(SSL_CTX *ctx, unsigned int ext_type,
0f113f3e MC	474	custom_ext_add_cb add_cb,
0f113f3e MC	475	custom_ext_free_cb free_cb,
0cfefe4b	476	void *add_arg,
a230b26e	477	custom_ext_parse_cb parse_cb, void *parse_arg)
0f113f3e	478	{
787d9ec7	479	return add_old_custom_ext(ctx, ENDPOINT_SERVER, ext_type,
43ae5eed MC	480	SSL_EXT_TLS1_2_AND_BELOW_ONLY
	481	\| SSL_EXT_CLIENT_HELLO
	482	\| SSL_EXT_TLS1_2_SERVER_HELLO
	483	\| SSL_EXT_IGNORE_ON_RESUMPTION,
	484	add_cb, free_cb, add_arg, parse_cb, parse_arg);
	485	}
	486
	487	int SSL_CTX_add_custom_ext(SSL_CTX *ctx, unsigned int ext_type,
	488	unsigned int context,
cd17bb19 MC	489	SSL_custom_ext_add_cb_ex add_cb,
cd17bb19 MC	490	SSL_custom_ext_free_cb_ex free_cb,
43ae5eed	491	void *add_arg,
cd17bb19	492	SSL_custom_ext_parse_cb_ex parse_cb, void *parse_arg)
43ae5eed	493	{
f6da3bbf MC	494	return ossl_tls_add_custom_ext_intern(ctx, NULL, ENDPOINT_BOTH, ext_type,
	495	context, add_cb, free_cb, add_arg,
	496	parse_cb, parse_arg);
0f113f3e	497	}
c846a5f5 DSH	498
c846a5f5 DSH	499	int SSL_extension_supported(unsigned int ext_type)
0f113f3e MC	500	{
	501	switch (ext_type) {
	502	/* Internally supported extensions. */
	503	case TLSEXT_TYPE_application_layer_protocol_negotiation:
	504	case TLSEXT_TYPE_ec_point_formats:
de4d764e	505	case TLSEXT_TYPE_supported_groups:
36abb6a2	506	case TLSEXT_TYPE_key_share:
1595ca02	507	#ifndef OPENSSL_NO_NEXTPROTONEG
0f113f3e	508	case TLSEXT_TYPE_next_proto_neg:
1595ca02	509	#endif
0f113f3e MC	510	case TLSEXT_TYPE_padding:
0f113f3e MC	511	case TLSEXT_TYPE_renegotiate:
cf72c757	512	case TLSEXT_TYPE_max_fragment_length:
0f113f3e MC	513	case TLSEXT_TYPE_server_name:
	514	case TLSEXT_TYPE_session_ticket:
	515	case TLSEXT_TYPE_signature_algorithms:
36abb6a2	516	#ifndef OPENSSL_NO_SRP
0f113f3e	517	case TLSEXT_TYPE_srp:
36abb6a2 MC	518	#endif
36abb6a2 MC	519	#ifndef OPENSSL_NO_OCSP
0f113f3e	520	case TLSEXT_TYPE_status_request:
36abb6a2 MC	521	#endif
36abb6a2 MC	522	#ifndef OPENSSL_NO_CT
ed29e82a	523	case TLSEXT_TYPE_signed_certificate_timestamp:
36abb6a2 MC	524	#endif
36abb6a2 MC	525	#ifndef OPENSSL_NO_SRTP
0f113f3e	526	case TLSEXT_TYPE_use_srtp:
e481f9b9	527	#endif
36abb6a2	528	case TLSEXT_TYPE_encrypt_then_mac:
91b60e2a MC	529	case TLSEXT_TYPE_supported_versions:
91b60e2a MC	530	case TLSEXT_TYPE_extended_master_secret:
36abb6a2 MC	531	case TLSEXT_TYPE_psk_kex_modes:
	532	case TLSEXT_TYPE_cookie:
	533	case TLSEXT_TYPE_early_data:
	534	case TLSEXT_TYPE_certificate_authorities:
	535	case TLSEXT_TYPE_psk:
9d75dce3	536	case TLSEXT_TYPE_post_handshake_auth:
b67cb09f	537	case TLSEXT_TYPE_compress_certificate:
3c95ef22 TS	538	case TLSEXT_TYPE_client_cert_type:
3c95ef22 TS	539	case TLSEXT_TYPE_server_cert_type:
0f113f3e MC	540	return 1;
	541	default:
	542	return 0;
	543	}
	544	}